Reliability

Question 1

What is reliability ?

Answer 1

• It is a measure of consistency, results are consistent when replicated.

Question 2

What can make a study lack reliability ?

Answer 2

• Extraneous variables - any variable not being investigated that has the potential to affect the outcome of a research study.
• The test or questionnaire used to measure the DV is itself unreliable.

Question 3

What are the types of reliability ?

Answer 3

• External reliability- assesses consistency of a measure from one use to another.
• Internal reliability - How consistent the individual items on a test or questionnaire are with each other.

Question 4

How to assess internal reliability ?

Answer 4

• The split-half is used to assess the internal reliability of a test. The split-half method takes one test and divides it into two sections. This can be even/odd numbered questions or first half/second half.
• Test the strength of the correlation between the two parts of the measure
• A strong correlation indicates internal reliability.

Question 5

How to assess external reliability ?

Answer 5

• Test-retest - repeat the study using the same procedures/measuring devices at different times and test correlaltion between two versions.

Question 6

What is inter-rater reliability ?

Answer 6

Two (or more) observers record behaviours
during the same observation using the same behavioural categories; then, they test
the correlation between each tally of behaviour to identify if the behavioural
categories are appropriately operationalised.

Question 7

What is does it mean by improving reliability ?

Answer 7

Changes psychologists can make to design of studies.

Question 8

How can you improve reliability in observation?

Answer 8

• By training the observers to improve accuracy in assigning particular observed behaviour to correct behavioural category, so can use pilot studies or operationalisation.

Question 9

How can you improve reliability in interviews?

Answer 9

• Using a structured interview easy to repliacte and quantify if same questions used

Question 10

How can you improve reliability in questionnaires ?

Answer 10

• Questionnaires: Use closed questions to reduce the range of possible responses, and
  if there is an established questionnaire that tests for what you need to measure, use
  that rather than creating a new test.

Question 11

How can you improve reliability in experiments ?

Answer 11

Experiments: Use standardised procedures for each participant, so they all have the
same experience. For example, keep what is said to the participants the same (by
using a script) and environmental conditions the same. Use established tests as measures rather than creating a new test.